Process and device for concentrating incrusting or corrosive solutions



Aug. 28, 1928. 1,682,265

P. BRINGHENTI PROCESS AND DEVICE FOR CONCENTRATING INCHUSTING OR CORROSIVE SOLUTIONS FiledJah. 15, 1926 2 SheetS-Sheet 1 Aug. 28, 1928. 1,682,265

- P. BRINGHENTI PROCESS AND DEVICE FOR CONCENTRATING INGRUSTING OR CORROSIVE SOLUTIONS Filed Jan. 15, 1926 2 Sheets-Sheet 2 Patented Aug. 28, 1928.

UNITED STATES 1,682,265 PATENT OFFICE;

PLINIO BBDTGHENTI, 0F IILLN, ITALY.

PROCESS AND DEVICE FOR CONCENTBATING INCBUSTING OB CORBOIVE SOLUTIONS.

Application filed January 15, 1886, Serial No. 81,599, and in Italy October 28, 1925.

This invention relates toa process of and a paratus for the concentration of solutions 0? the kind wherein the solution to-be concentrated is subjected to direct treatment with a continuous stream of liquid heat transmitting medium, and the object of the mvention is to provide an improved process of the kind referred to and-apparatus therefor.

The invention consists in heating the solution to be concentrated at a temperature lower than its boiling point by continuously introducing therein a stream of finely d1- vided heat transmitting liquid lighter than the solution and insoluble therein, floating off the said liquid, separating entrained solution therefrom, heating the separated l1q u1d by direct contact with a hot aseous medium so as to restore heat thereto 0st to the solution, spraying the heated solutlon into a vessel whereby it is part1 evaporated, carrying oil the vapours evolve from the evaporation, returning the partly evaporated solution to the cycle for further concentration by treatment with the finely divided heated liquid repeating the cycle as often as desired and running of the concentrated solution.

The invention also consists in apparatus for carrying out the process.

The liquid which is most suitable foruse as heat carrier is melted araflin wax, a substance which is chemica ly inert or nearly so, only being attacked when heated by strong oxidizing agents, such as nitric acid,'sulphuric acid and halogens, which moreover convert it into carbon dioxide and water, that is to say substances which do not remain in the solution. Further paraflin wax has a s ecific gravity of 0.78 and therefore floats easily upon all aqueous solutions.

Fi ures 1 to 4 in the accompanying drawing ilustrate two forms of construction of the concentration device according to the invention. I

Figures 1 and 2 are two views, in vertical projection, of a single acting device.

Figures 3 and 4 are an elevation and a plan respectively of a device with several concentrators.

The device shown in Figures 1 and 2 operates in the following manner.

The cylindrical vessel 0 is filled through the o ening B with liquid paraflin wax: the para n wax melts, according to the quality,

etween 40 to C. In this vessel it IS heated from the outside by means of either.

steam or hot gases admitted through the pipe F. A circulation pump P forces the parafiin thus heated into the cylindrical vessel R, which is almost completely filled from the funnel J with the liquid to be concentrated.-

- The araffin, subdivided into minute threads y the perforated coil 8 rises here through the solution and gives up heat to it; it then enters, through the. pi e t mto the se arator S where it gives up y difference in densit the solution it may have carried with it wh1ch solution returns to B through the pipe an; it finally reaches the vessel G through the 1pe M to be again heated there.

T e solution thus heated descends through the ipe T terminatin at its lower part in a per orated cap and fa Is in a fine spray into the vessel V where it is artly caporized. While the vapour produced escapes through the p1 e A, the non-evaporated solution is taken y the pump P and led back through the tube I into the vessel R in order to undergo in it a subsequent concentrating operation. The water which issues from A in the form of vapour is continually re laced in the vessel R by means of a. funnel by a corresponding amount of solution.

The process is continued in this way until the desired degree of concentration is obtamed. The vessel R is then emptied and the operation recommenced.

The device shown in Fi ures 3 and 4 is similar to the previous one, at is formed of a number of concentrators. In these figures the reference numerals employed in the previous case have been applied to similar parts.

This device operates as follows:

The solution is admitted into the horizontal gylindrical vessel R by means of the funnel while the pump P sends liquid parafiin into the lower part of the same vessel, which parafiin has been heated 'in the vessel C in the manner previously described. This paraflin rises in R through the solution and regains, through the tube t the vessel 0 where it is again heated, after having passed through the separator S inwhich it gives up any solution it may have carried along with it, which solution returns to R;

The heated solution then descends through the tube T and falls in a spray into the vessel In this vessel (3 the vapour is condensed and gives up'its heat to the paraifin which falls-mto lit in the. form of a rain through the tube t from the vessel 12,. The water of condensation. formed passes out at the bottom and the duct 6 leads it to the v.es sel 0,; the paraflin thus heated by the vapour is forced by the pump P, through the tube a, to heat the solution contained in the vessel R The solution heated in R descends into V and artly evaporates in it. The vapour liberate asses through A, into C and heats the parafliii which falls into it in a rain, coming from R,. The residual solution is forced b the pump P, throu h 1*, into the vessel R 'l he vapour produce in the last vaporizer V passes directly into the mixture condenser K where it is condensed.

The pumps P P P, provide for the circulation of the solution in each of the three concentrating roups, if there are three, while the pumps P P, provide in them for the circulation of the liquid paraflin. The ducts m, and m serve for the passa e of the solution from the first tothe secon and from the latter to the third concentrator. The concentrated solution is drawn off through the pipe D. The valves a and a, at the head of the vessels C and C, respectively lead to the condenser K the ases which enter into or are produced in the pieces of apparatus.

The osition of the reheating vessels R, R R an the corresponding Vaporizers V, V V, may be changed by placing each reheater R beneath its vaporizer V. n this way as the pressure existing in R is greater than in V the solution will rise from R to V reducing to a minimum the work done by the pumps P.,

The cylindrical shape of all the vessels, without mternal tubes enables them to be constructed of the most suitable material for each solution. The production I and efliciency of the apparatus are at all times constant as the amount of heat transmitted to the solution does not vary.

By means of this process any neutral or slightl alkaline for acid solution may be treate even those most liable to incrust withcoming aesaseu out there being any fear of objectionable conditions developing.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:'-

g r 1. In the process of concentrating solutions wherein the solution is directly treated with. a liquid heat transmitting medium, heating the solution to be .concentrated at a temperature lower than its boiling point by continuously introducing therein a stream of finely divided heat transmittin liquid lighter than the solution and insofuble therein; floatin ofi the said liquid, separating entraine solution therefrom, heating the se arated liquid by direct contact with a hot aseous medium so as to restore heat thereto 0st to the solution; spraying the heated solution into a" vessel whereby it is partly evaporated, carrying oflf the vapours evolved from the evaporation, returnin the partly concentrated solution to the cy e for further concentration'by treatment with the finely divided heated liquid repeating the cycle as often as desired and running oif the concentrated solution.

2. Apparatus for concentrating solutions comprising a vessel to contain the solution, a second vessel to contain the heat transmitting liquid, means for heating the said liquid, a pump adapted to transfer the said heated liquid to the first mentioned vessel, spraying means within said first vessel, an evaporatitng vessel in communication with said first vessel, spraying means within said evaporating vessel, a dpump adapted to return partly concentrate solution from the evaporating vessel to the first vessel, an outlet for the heat transmitting liquid from said first vessel, a separator connected to said outlet adapted to separate entrained solution from the heat transmitting liquid, and return same to said first vessel, and adapted to return the heat transmitting liquid to the second vessel.

In testimony whereoef I have signed my name to this specification.

PLINIO BRINGHENTI. 

